Hydraulic pumping jack



July 31, 1951 wHn-E 2,562,837

HYDRAULIC PUMPING JACK Fiied Oct. 50, 1945 3 SheetsSheet l 4:. 7 g /9INVENTOR.

IRA MORGAN WH/ TE @zwqzw ATTORNEYS July 31, 1951 1, M, w E 2,562,837

HYDRAULIC PUMPING JACK INVENTOR. 1E4 MORGAN WHITE ATTORNE Y5 July 31,1951 l. M. WHITE 2,562,837

HYDRAULIC PUMPING JACK Filed Oct. 50, 1945 3 Sheets-Sheet 3 v INVENTOR.[RA MORGAN WHITE Y 242-. wkzm ak ATTORNEYS Patented July 31, 1951HYDRAULIC PUIVIPING JACK Ira Morgan White, Oakland, Calif., assignor toThe Pelton Water Wheel Company, San Francisco, Calii'., a corporation ofCalifornia Application October 30, 1945, Serial N 0. 625,502

6 Claims. (Cl. 60-52 This invention relates in general to a hydraulicdeep well pumping jack system including a hydraulic jack; a balancingpressure tank, a constant displacement pump and an automatic controlvalve. The balancing pressure tank of the system is maintained at apressure such that the resulting lifting force of the pressure appliedin the hydraulic jack would be equal to the rod weight plus one-half ofthe fluid weight normally lifted by the jack. The operating pump andcontrol valve are disposed between the jack and the balancing tank sothat operation of the pump and control valve to produce flow from thetank to the jack will lift the piston in the jacket while operation ofthe pump and control valve to produce flow from the jack to the tankwill lower the piston in the jack. A special hydraulic control mechanismis provided to reverse automatically the action as the jack reaches theterminal point of each end of the stroke. By maintaining the pressure inthe balancing tank as described above, the pump is subjected to asubstantially constant load during the upstroke and downstroke of theack. During the upstroke the pump must develop suflicient pressure whichwhen applied to the jack will augment the balancing tank pressure andlift the entire rod plus the fluid load. Conversely, during thedownstroke, the pump must sufficiently reduce the pressure within thejack so as to remove fluid from the jack so that the load on the jackwill be reduced to the rod load only.

In addition to the normal operating devices required for the hydraulicpumping jack, the jack is provided with a safety feature in order tobring about shutdown of the jack in the event of rod breakage andconsequent loss of load to the jack. If such a device were not provided,the pump would be subjected to excessive overdrive conditions in theevent of loss of part of the load supported by the jack. For example, arod breakage during the upstroke of the jack could reduce the load onthe pump discharge to below the pump suction supplied by the balancingtank. This condition could possibly set about destructive forces if therod breakage control device were not incorporated.

In general then, the object of this invention is the provision in ahydraulic pumping jack system of the character described, of means forprotecting the system from damage by reason of abnormal operatingconditions, such as sucker rod breakage.

More specifically, the object of this invention is the provision in ahydraulic pumping jack system of the character described, of a normallyopen valve which will automatically close in response to predeterminedsub-normal pressure in the jack.

The invention possesses other advantageous.

features, some of which with the foregoing will be set forth at lengthin the following description where that form of the invention, which hasbeen selected for illustration in the drawings accompanying and forminga part of the present specification, is outlined in full. In saiddrawings, one form of the invention is shown, but it is to be understoodthat it is not limited tosuch form, since the invention, as set forth inthe claims, may be embodied in a plurality of forms.

Referring to the drawings:

Fig. 1 diagrammatically illustrates a hydraulic pumping jack systemembodying the objects of my invention shown with the system in theupstroke portion of its cycle.

Fig. 2 is a view similar to Fig. 1 but showing the system in thedownstroke portion .of its cycle.

Fig. 3 is an enlarged detail longitudinal section of the automatic valveincorporated in the system to safeguard it due to any damage which mightotherwise occur as a result of any abnormal differential pressures towhich the system might be subjected.

In general, the system shown in these figures includes a hydraulic jackA, the piston of which carries a polished rod; a balanced pressure tankB, maintained at a pressure sufficient to produce a lifting load in thejack equal to the rod load plus one-half of the fluid load supported bythe jack; a constant displacement pump C, capable of producing apressure above the tank pressure sufficient to lift the rod weight plusthe fluid weight, and also capable of reducing the pressure in the jackbelow the pressure tank so as to permit the sucker rod to drop; acontrol valve D, disposed between the pump and the balanced pressuretank for alternately delivering fluid from the pressure tank to thehydraulic jack on the upstroke of the jack and then from the jack to thetank on the downstroke of the jack; a pilot valve E, responsivedifferentially and hydraulically to the terminal movements of thehydraulic -jack piston for operating the main control valve; and ashutoff valve F, for closing the circuit between the balanced-pressuretank and the main control valve in response to any predeterminedabnormal differential pressure existing in the system.

associated with the cylinders ll and 3!.

As disclosed in Figs. 1 and 2, the hydraulic jack A includes a cylinderI, with which is operatively associated a piston 2. Depending from thepiston I through a suitable stuiflng box in the lower end of thecylinder I, is a polished rod 8, to which is fastened the sucker rod ofan oil well pump. The cylinder I is provided on its lower end with afluid operating medium inlet and outlet port 4 and at its upper end witha fluid outlet port I communicating through a check valve I, line I andcheck valve I with an intake port provided in the lower end of thecylinder above the port I. Also provided on the upper end of thecylinder l are a pair of longitudinally spaced outlet drainage ports IIand I2, communicating (through line ll, cheekvalve ll, line ll. scavenin pump It, line ll, check valve It and line II) with an intake port IIprovided in the lower end of the balancing pressure tank B.

The pump C is of the constant displacement type, including a pair ofopposed suction chambers I2 and 23 and a discharge compartment 24, andis adapted to be driven by any suitable power means. The suctionchambers 22 and II are provided respectively with inlet ports 26 and IIand the discharge compartment with a discharge outlet 11 and with arelief valve outlet 2| communicating through a relief valve 2! with aninlet port II associated with the suction chamber 23.

The main control valve D is of the piston type including a main cylinder32 provided with five longitudinally spaced annular channels II, a, II,It and 31. Provided on either end of the valve D, coaxially with themain cylinder 32, are smaller cylinders It and It. operativelyassociated with the main cylinder 32 are a pair of longitudinally spacedpistons ll and 42 mounted on a piston shaft ll, and carried on the endsof the shaft 41 arepistons M and I! operatively The simultaneousmovement of the pistons ll, 42, 44 and I! from their positions as shownin Fig. 1 to the positions shown in Fig. 2 is effected through the pilotvalve E in a manner which will be described later in connection with thedescription of the valve E. Communication between the lower end of thebalanced pressure tank B and the annular channel It is establishedthrough the normally open port It of the shutoff valve 1''. Fluid fromthe balanced pressure tank B flows through the valvefF, line 4'l andport a into the annular channel it. From this channel the fluid passesinto the channel 31, through a port 31a associated with the channel 31and through a line I and the inlet port 2' into the suction chamber 23.The line It communicates through a line ll with a line II which, inturn. communicates with the inlet port of the suction chamber 22 andwith a port "a associated with the annular chamber I3. It will,therefore, be seen that the fluid passing through the channels ll and IIof the main control valve will be delivered to both of the suctionchambers 22 and 23 of the pump C. The pump C then delivers this fluidthrough its outlet port 21, through a line 52 and a port 350 associatedwith the channel into the channel 35. From the channel II. the fluidpasses through the channel 34, through a port a associated with thischannel and through a line 53 and the port 4, into the lower end of thecylinder I. In this position the pump C operates to pass fluid from thetank B through the main control valve D into the lower end of thecylinder i, thereby to raise the piston}.

past the piston 2 is delivered through ports H' and i2, line It, checkvalve l4, line ll, scavenging pump IO, line ll, check valve II, and linell through the port 2| associated with the lower end of the tank B intothe tank B. In this connection. it should be noted that the scavengingpump it is operated so as to maintain substantially atmospheric pressureon the check valve ll.

When the piston 2 rises above the port I. fluid under the main pumppressure passes through port I, check valve 6, the upper portion of theline I, and line 84 to the left end port ll associated with the pilotvalve E.

a The pilot valve E is of the same type as the main control valve D,including a main cylinder 56 with which are operatively associated threelongitudinally spaced coaxial pistons II. II and SI, fastened to acommon shaft II. Formed on the right end of the pilot valve E is acylinder I of a smaller diameter than the main cylinder II and which isprovided with an outlet port I. operatively associated with the cylindern is a piston t4, fastened to and forming a continuation of the rightend of the shaft I. Communication between the port a and the port 30bassociated with the channel ll of the main control valve D, isestablished by a line I. With the main valve in the position as shown inPig. 1, fluid from the tank B is delivered from the channel it throughthe line 6' to the small cylinder it. However, since the area of thepiston N is less than the area of the piston 51. the pump dischargefluid pressure in line ll will cause pistons I1, I, II and N to move tothe right to assume the position shown in Fig. 2.

With the pilot valve E in the position as shown in Fig. 2, and the maincontrol valve in the position as shown in Fig. 1, fluid under tank pressure passes upwardly through line 41, port 30b, line 60, valve E andline 01 into the left end cylinder ll of the main valve D to force thepistons ll. 42, 44 and II to the right, as shown in Fig. 2. Due to theright hand movement of the piston I, fluid contained in its cylinder llpasses through line '8, pilot valve E, line 0!, line H, to the drainlineI, from'which the pressure is increased by the scavenging pump llsuflicient to replace the fluid in the bottom of the tank B through thecheck valve ll.

With main valve D, as well as pilot valve I, in the positions as shownin Fig. 2, the pump C operates to draw liquid from the lower end of thehydraulic Jack cylinder i, through port 4, upwardly through line II,through the intercommunicating ports a and Ila of the main control valveD, and into the suction chambers 22 and II of the pump. The pump thenoperates to deliver this fluid from its discharge compartment 24 throughthe intercommunicating ports lie and "a of the main control valve D,line 41 and the normally open port 48 of the shutoif valve 1''. backinto the balancing tank B.

When the piston 2 of the hydraulic jack passes the check valve 6 on itsdownward stroke. no effect is produced on pilot valve E because checkvalve 8 does not permit the flow of fluid back into the cylinder I.When, however, the piston 2 passes port Q'on its downward stroke, pilotvalve E is placed in communication (through line I, check valve 8,cylinder l, line ll, check valve ll, scavenging pump II and check valvell) with the lower end of the tank B. Concurrently, the right hand endof small piston 64 of the pilot valve is subjected to tank pressurethrough the intercommunicating ports 35a and 39b of the main controlvalve D and through the line 65. Since at this point in the cycle ofoperation the left end of the piston 51 is only under the influence ofsubstantially atmospheric pressure, the pump pressure on the piston 64moves it to the left, whereby the pilot valve E assumes its originalposition as shown in Fig. 1. In this latter position of the system,fluid under tank pressure passes (through line 41, theintercommunicating ports 39a and 36b of the main valve, line 66, theintercommunicating ports I2 and 13 of the pilot valve and line 68) tothe right end cylinder 39 of the main valve. Since the left end piston44 of this valve is now in communication with the drain system (throughline 61, the intercommunicating ports 14 and 15 of the pilot valve, line99 and line 1|) the tank pressure on the piston 45 results in movingthis piston and its associated pistons to theleft to assume theiroriginal position as shown in Fig. 1. The system so far described is incondition to repeat the complete cycle of operation as above disclosed.

As already stated, the static load on the polished rod 3 may at times beas high as or greater than 20,000 pounds and, therefore, when due to abreakage in the sucker rod any appreciable portion of this load is lost,the main pump would of course be subjected to an excessive overdrivecondition on the upstroke. To safeguard the pump and its associatedmechanism against such a contingency, the shutoff valve F is inserted inthe line between the tank B and the main valve D, with its main port 46normally open. The shutoff valve F, as best shown in Fig. 3, comprises agenerally S-shaped casing 9|, provided at either end with flanged ports46 and 92, the port 45 being connected with the lower end of tank B andthe port 82 with line 41, as shown in Figs. 1 and 2. Formed on one sideof the cas ing BI is a cylinder 83, the left end of which is closed by acap 84, forming an internal flange 84a having an internal diametersomewhat less than the diameter of the cylinder 83. The cylinder 83 isprovided at its right end with a port 95 communicating with lines 69 andII, and the left end of the cylinder is connected through a port 86formed in the cap 84 to a pipe 8! connecting with line 53. In pipe 81 isinserted a three-way valve 88, all as shown in Figs. 1 and 2. Extendingthrough the right end of the cylinder 83 is a piston rod 89, and securedto the left end of this red is a piston 9| operatively disposed withincylinder 83. Fastened to the right end of the rod 89 is a valve closuremember 92 adapted to seal against a seat 93, formed in the outer end ofport 46.

The stem 89 is so proportioned with respect to the piston 9| that undernormal conditions of operation, the force applied on the head end of thepiston 9| is greater than the combined pressures acting on the rod endof the piston 9| and the tank pressure acting on the valve member 92,especially on the rod portion 89 thereof, the resultant force being suchas to hold the piston Si in the extreme right position. Consequently,the valve 92 remains in the open position. If, however, the sucker rodattached to the polished rod 3 breaks and the polished rod is relievedof a portion of its load, there will be a correspond ing decrease in thepressure within the jack cylinder Under these abnormal conditions, thereduced pressure under the jack piston and effective upon the head endof the piston 9| is overcome by the pressure in the balancing tank Bacting first upon the rod 99 and, as the valve 92 moves toward closedposition and reduces the pressure in the passage around the stem 89,acting finally upon the tank side of the valve 92. This is suflicient toclose the shut on valve F during the abnormal upstroke of the jack, and

thereby prevent the further passage of fiuid from the tank B to thecontrol and pilot valves D and E and to the main pump C. The shutoffvalve F will remain closed until the pressures on either side of itsclosure member 92 have been substantially equalized. In the event ofbreakage in the sucker rod, this can only be done by dismantling andrepairing the deep well pumping equipment.

The valve F can also be closed by turning the three-way valve 98 so thatthe left end of the cylinder 83 is placed in communication through thevalve 88 with the line ll of the drain system, thereby to reduce thepressure on the left end of the piston 9| substantially to atmosphericpressure. In this connection, the valve F is provided with an auxiliarynormally closed by-pass valve 93 disposed in a line 94 connected betweenthe two sides of the closure member 92. To open the shutoff valve F, thethree-way valve 89 is turned to its normal position in communicationwith the jack cylinder and the by-pass valve 93 is turned to its openposition so as to equalize the pressure on both sides of the closurememher 92. The shutoff valve F will then open, making it possible to putthe jack A into operation by starting the pump C.

As a further safety measure, the pump C is provided'with a relief valve29 across its suction and discharge sides to protect the system in theevent of any blockage therein.

I claim:

1. A hydraulic pumping jack system comprising: a hydraulic jackcylinder; a piston therein; a balancing pressure tank; a line betweensaid jack cylinder and said tank; a pump disposed in said line; valvemeans responsive to the operation of said piston for periodicallyreversing the connections of said pump so as to cause a flow of fluidfrom said tank to said cylinder on the upstroke of said piston and thenfrom the cylinder to the tank on the downstroke of said piston; ashutoff valve interposed in said line between said tank and said pump;and means responsive to a predetermined pressure difference between saidhydraulic Jack cylinder and said tank for closing said shutoff valve.

2. A hydraulic pumping jack system comprising: a hydraulic jackcylinder; a piston therein; a balancing pressure tank; a control valve;a line connecting said control valve to said cylinder and to said tank;a'pump connected to said control valve, said control valve beingeffective periodically to reverse the connections of said pump with saidline so that fluid from the tank is pumped to the jack cylinder on theupstroke of said piston and on the downstroke of said piston 'fiuid fromthe jack cylinder is pumped to the tank; a shutoff valve disposed in theline between .said tank and said control valve; and means responsive topressure in said line between said hydraulic jack cylinder and saidcontrol valve and to pressure in said line between said tank and saidcontrol valve for operating said shutoff valve.

3. A hydraulic pumping jack'system compris ing: a hydraulic jackcylinder; a piston therein; a balancing pressure tank; a pump; a linebetween said jack cylinder and said tank; a control asoassv valve iorconnecting alternately the low pressure side of said pump with said tankand the high pressure side of said pump with said jack cylinder on theupstroke of said piston and then the low pressure side of the pump withthe jack cylinder and the high pressure side of the pump with the tankon the downstroke of said piston; means for actuating said control valvein response to the operation of said piston; a shutoff valve disposed inthe line between the tank and the pump; means responsive to apredetermined pressure difierence between said tank and said hydraulicjack cylinder for closing said shutoil' valve; and a relief valveinterposed between the low pressure and high pressure sides of saidpump.

4. A hydraulic pumping jack system comprismg: a hydraulic jack cylinder;a piston therein; a balancing pressure tank; a pump having an inlet andan outlet; valve means responsive to the operation of said piston forcontrolling fiow between said pump, said cylinder, and said tank;conduits connecting said pump inlet and outlet to said valve means; afirst line interconnecting said cylinder and said valve means; a secondline interconnecting said tank and said valve means; a shutol! valve insaid second line; a differential pressure-responsive member foroperating said shut-oi! valve; means for exposing one side of saidpressure-responsive member to pressure in said first line; and means forexposing the other side of said pressure-responsive member to pressurein said second line.

5. A hydraulic pumping jack system comprising: a hydraulic jackcylinder; a piston therein; a balancing pressure tank; a pump having aninlet and an outlet; valve means responsive to the operation of saidpiston for controlling fiow between said pump, said cylinder, and saidtank; conduits connecting said pump inlet and outlet to said valvemeans; a first line interconnecting said cylinder and said valve means;a second line interconnecting said tank and said valve means; ashut-oil. valve in said second line; a pressureresponsive member havinga large diameter portion, an intermediate portion, and a small diameterportion for operating said shutoi! valve; means for subjecting saidintermediate portion to substantially atmospheric pressure; means forsubjecting said large diameter portion to pressure in said first line;and means for subjecting said small diameter portion to pressure in saidsecond line.

6. A hydraulic pumping jack system comprising: a hydraulic jackcylinder; a piston movable therein; a balancing pressure tank; a linebetween said cylinder and said tank; a pump having an inlet and anoutlet; a valve responsive to the position of said piston in saidcylinder for connecting said pump outlet to said cylinder and said pumpinlet to said tank and vice versa; means responsive to a first pressureand to a second pressure for controlling flow in said line between saidtank and said pump; and means for subjecting said controlling means topressure between said tank and said pump as a first pressure and topressure between said cylinder and said pump as a second pressure.

IRA MORGAN WHITE.

REFERENCES CITED The following references are of record in the file oi!this patent:

UNITED s'rs'rns PATENTS Number Name Date 1,290,722 Doble Jan. 7, 19191,842,961 Coppus Jan. 26, 1932 1,988,164 Cummins Jan. 15, 1935 2,277,761Hubbard Mar. 31, 1942 2,325,138 Kyle July 27, 1943 2,470,253 Kyle May17, 1949

